We've all been there: you ring a call centre to inquire about an account, only to realise you don't have your reference number.
Consumers, increasingly bombarded with booking, transaction and security codes, can be forgiven for not having every number at their fingertips.
Unless they're calling Qantas, that is.
As passenger James Wilkie recently discovered, failing to provide a booking reference number means he will be forced to forfeit a flight credit worth almost $800.
"I've called Qantas half a dozen times and emailed the helpline, but they won't give me any information without a booking reference number," he said. "They tell me that without [it] they're not willing to go any further with the conversation."
Mr Wilkie's frustration with Qantas began in October, when he was about to board a plane from Melbourne to Singapore, where he was living at the time.
He was travelling on a one-way ticket and was told by staff that he needed an ongoing flight from Singapore due to the country's immigration rules.
"They said all I had to do was buy a return ticket and when I'm back in Singapore to contact Qantas, cancel the ticket and they'll put it in credit," he said.
Mr Wilkie bought a ticket for $778 over the counter and a week later cancelled it, with the credit applied to his account. But when he recently contacted the airline to ask about the credit - after losing the flight paperwork while moving house - staff refused to discuss his account, citing privacy reasons.
Mr Wilkie was told he needed to provide the booking reference number (located on the lost paperwork), ticket number (also lost) or a Qantas frequent flyer number (he is not a member). Failing that, if he knew the flight number (on the lost paperwork) the airline could email the itinerary to the address provided (no email was given when the ticket was bought).
In three separate emails from Qantas, staff said "strict guidelines" prevented them from discussing the account and told Mr Wilkie to call back with the booking number.
The experience has left Mr Wilkie vowing to boycott Qantas, which recently posted a $2.8 billion net loss for the year.
"There's a credit there and all I want is to use it," he said. "I've given all my personal information and more: name; date of transaction; passport number; credit card number. Still they won't help."
This is the second embarrassment to Qantas' customer service highlighted in as many days. On Wednesday, Fairfax Media reported that a passenger received an insultingly dismissive apology letter from the airline more than a month and a half after complaining about long flight delays and a broken entertainment system.
Qantas said Mr Wilkie's circumstances were rare and that the matter would be investigated.
"It's unusual for a customer to be unable to provide these details, but where that's not the case we're happy to look into it further to try to find a resolution," a spokesman said.
"We apologise for any frustration caused and we're now pursuing this internally."